Module harmonic_function 

Harmonic function labels and the Roman numerals they stand for: music21’s analysis.harmonicFunction.

A label is a function — tonic, subdominant or dominant — in major (capital) or minor (small), optionally with its Parallelklang (p/P, a third below) or Gegenklang (g/G, a third above):

  T  I     Tp vi     Tg iii
  S  IV    Sp ii     Sg vi
  D  V     Dp iii    Dg bvii

Where the figure depends on the mode — the third, sixth and seventh degrees — a minor key has its own table.

Enums

FunctionDetail

Whether a lookup keeps the whole label or only its main function.

HarmonicFunction

One of the eighteen harmonic function labels.